If you're ever trying to organise a surprise party, it might be an idea not to mention it to Ben Page of Ipsos-Mori. Having told the world the other day that two of his firm's competitors were about to publish polls showing Remain in the lead, he's spent the last couple of hours undermining the embargo on his own poll by dropping broad hints on Twitter that it was going to show a swing to Remain. In all honesty, though, given that Leave have been dropping like a stone on the betting markets, it's quite striking that the Remain lead is as low as it is - it's lower than the ComRes phone poll reported last night (in spite of the fact that the fieldwork is much more up to date), and it's in 'statistical tie' territory. Depending on the reports they're getting about turnout on the ground, the Leave campaign may feel this still puts them in with a genuine shout.
Should the United Kingdom remain a member of the European Union or leave the European Union?
Remain 49% (+6)
Leave 46% (-3)
Leave 46% (-3)
UPDATE : The Populus poll is much better for Remain -
That's a real oddity, because it's an online poll, and the fieldwork is only marginally more up to date than the YouGov and Opinium online polls that had a roughly 50/50 split. There have been some suggestions that Populus (who haven't published an EU poll for months) have been doing the private polling for the Remain campaign, so if those polls have been quietly doing the rounds in elite circles and have been markedly better for Remain all along, that could explain the odd sense of certainty in some quarters about today's outcome. But it's worth remembering that private polling isn't inherently more accurate than public polling. It'll be interesting to see whether Populus have been doing anything unusual, and perhaps reassigning Don't Knows to Remain on the basis of answers to supplementary questions in the way that ComRes did last night.
UPDATE : We now have a bit more detail from the Ipsos-Mori poll (although not the full datasets yet). The most intriguing point is that when a slightly different turnout filter is used, the Remain lead drops to 2% - a 51% to 49% split with Don't Knows excluded.
It's human nature to react to polls in the order in which we see them, but it should be stressed that the Ipsos-Mori poll is just as up-to-date as the Populus poll - both were conducted yesterday and the day before. And of course Ipsos-Mori is a telephone poll, so in the ultimate role-reversal it's actually the telephone poll that's keeping Leave's hopes alive.